Too many persons are lost at sea due to accidents and lack of efficiently informing rescue teams of their fatal situation.
These situations become particularly difficult to deal with as they occur far away offshore, in hostile environmental conditions, with limited local resources for treatment.
The detection and location of an aircraft crash or maritime distress is of paramount importance to the search and rescue (SAR) teams and to the potential survivors. Studies show that while the initial survivors of an aircraft crash have less than a 10% chance of survival if rescue is delayed beyond two days, the survival rate is over 60% if the rescue can be accomplished within eight hours. Similar urgency applies in maritime distress situations, particularly where injuries have occurred. Furthermore, accurate location of the distress can significantly reduce both SAR costs and the exposure of rescue forces to hazardous conditions, and clearly improve efficiency. In view of this, Canada, France, Russia and the USA established the Cospas-Sarsat satellite system to reduce the time required to detect and locate SAR events world-wide.
Operational use of Cospas-Sarsat by SAR agencies started with the crash of a light aircraft in Canada, in which three people were rescued (Sep. 10, 1982). Since then, the System has been used for thousands of SAR events and has been instrumental in the rescue of over 17,000 lives worldwide.
Cospas-Sarsat is a satellite system designed to provide distress alert and location data to assist search and rescue (SAR) operations, using spacecraft and ground facilities to detect and locate the signals of distress beacons operating on 406 MHz or 121.5 MHz. The position of the distress and other related information is forwarded by the responsible Cospas-Sarsat Mission Control Centre (MCC) to the appropriate national SAR authorities. Its objective is to support all organizations in the world with responsibility for Search and Rescue (SAR) operations, whether at sea, in the air, or on land.
The Cospas-Sarsat System provides alerting services for the following types of beacons:                Emergency Locator Transmitters (ELTs) for aviation use        Emergency Position-Indicating Radio Beacons (EPIRBs) for maritime use        Personal Locator Beacons (PLBs) for applications which are neither aviation or maritime        
The use of satellites to detect and locate special-purpose radiobeacons, either manually activated or automatically activated by an aircraft crash or maritime distress situation, reduces the time required to alert the appropriate authorities and for final location of the distress site by the rescue team. The International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO) recommend that ships and aircraft carry Emergency Position Indicating Radio Beacon (EPIRBs) and Emergency Locator Transmitters (ELTs) respectively. In November 1988, the Conference of Contracting Governments to the International Convention for the Safety of Life at Sea, 1974 (SOLAS Convention) on the Global Maritime Distress and Safety System (1988 GMDSS Conference) adopted several amendments to the 1974 SOLAS Convention whereby, inter-alia, carriage of satellite EPIRBs on all convention ships of 300 tons and over became mandatory from 1 Aug. 1993.
Various national requirements also exist for the carriage of ELTs/EPIRBs on different types of craft not otherwise subject to international conventions, and some countries have authorized the use of Personal Locator Beacons (PLBs), 406 MHz emergency beacons for use on land, in remote or rugged areas.
Further information on COSPAS-SARSAT can be found at http://www.cospas-sarsat.org Modem navigation and communication systems, especially those based on satellites, such as COSPAS-SARSAT and GPS and Inmarsat and Iridium, provide reasonable solutions for vessels and aircraft in distress, however less efficient regarding to individuals that board such crafts and get into a distress situation, particularly persons over board (man over board=MOB), i.e. persons that fall to the sea from a vessel.
Although COSPAS-SARSAT supports a Portable Locator Beacon (PLB), which is provided, in different versions, by several manufacturers, this item is typically too bulky to be worn or carried continuously by crewmembers and passengers onboard craft, thus cannot provide an efficient solution for man-over-board situations, that may happen on the spot. Naturally, PLBs, as well as ELTs, EPIRBs and any other long range beacons, obtain a significant size and weight due to the need to communicate with far away satellites, hundreds and thousands kilometers away. Such a communications distance requires high power transmitters with accordingly high power sources. A high power transmitter requires relatively large components in order to dissipate heat and high capacity batteries which are large and heavy.
It is an object of the present invention to provide a system and method for the location of a person overboard, worldwide, being a passenger or a crewmember or even a single handed (i.e. sail alone) sailor, where this man-over-board wears a small and lightweight device such as a wristwatch, comfortable to be worn onboard and operate automatically in a man-over-board situation.
This invention, however, is not restricted to COSPAS-SARSAT. The prior art of location systems based on electronic methods typically applies wireless transmitters to objects that wished to be located, and a network of receivers that detect these transmissions and consequently calculate the object's position. For that purpose, “objects” might be persons, animals, pets, vehicles, containers, goods, valuables, mailed/delivered items, weapons, ammunition, hazardous materials and so on. Normally, these location methods can be divided into two major categories: a) short range; b) long range. Short range location systems typically operate in buildings, warehouses or campuses and enable using small, low power and low cost locatable transmitters, while long range systems may operate countrywide or even worldwide, yet typically require larger, high power radiating and consuming transmitters to be located. There is no special technological obstacle that disables the location of small and low power transmitters over a wide area, yet this would require deploying a large and dense network of receivers that is not economical and not practical, certainly not at sea.
U.S. Pat. No. 7,155,238 (Katz) discloses a method that enables locating small and low power transmitters over a wide area, without the need to deploy a large and dense network of receivers. The method is based on a two layer network: a) first layer obtains communication devices, possibly mobile, that can be located by a remote control station over a wide area network (WAN); b) second layer obtains short range transmitters that can communicate with said WAN communication devices. Upon establishing a connection between said short range transmitter and said WAN communication device, the remote control station can locate the communication device and consequently the short range transmitter. One embodiment of this invention relates to a fingernail size Bluetooth transmitter that can be located nationwide or worldwide, upon communicating with a Bluetooth enabled cellular device embedded with a GPS receiver. This method can be applied, for example, to a pet locating system: A dog's collar is embedded with a Bluetooth transceiver, obtaining a unique digital ID, and when it passes by a Bluetooth enabled mobile device, a wireless connection is established, the dog's transceiver's ID is reported to the mobile device and retransmitted to a remote control station, over the mobile network, where the mobile device location is determined by current means such as GPS, and accordingly the dog's location is determined. This way the dog is furnished with a small, low transmission power, low consuming power and low cost, yet can be located over a wide area, without deploying any infrastructure further than the cellular network. The shortcoming of this method is the uncertain availability of the process: the dog's location cannot be determined continuously, but only occasionally, as the dog gets close enough to a Bluetooth enabled mobile device. Thus, the availability of the dog's location service cannot be guaranteed beyond statistical expectations. Practically, a dog's location service might be acceptable in terms of “we expect to find your dog within half a day” or so, especially due to the advantages of this method in terms of dog's small and long ending battery life, as well as low cost, yet the uncertain availability of this method probably disqualifies it from been applied to locate people in case of distress.
U.S. Pat. No. 5,650,770 (Schlager et al.) and U.S. Pat. No. 5,963,130 (Schlager et al.) disclose a man-over-board alarm system, comprising a remote unit including a navigational receiver (such as GPS) and a base station, both configured to communicate with each other over a radio link. The base station includes measuring means for determining the distance to the remote unit and when it detects that this distance exceeds a predetermined limit, it causes a man-over-board alarm and displays the location of the remote unit.
This method has two significant limitations: a) it requires a remote unit that includes a navigational receiver (such as GPS); b) the range between the base station, where the alert is detected and the alarm is generated, and the remote unit (man overboard), is limited by the transmission power of the remote unit, which is typically not more than a few hundred meters. The latter definitely does not comply with single handed sailors needs.
U.S. Pat. No. 6,198,390 (Schlager et al.) discloses a man-over-board alarm system, comprising a remote unit including a navigational receiver (such as GPS) and a base station, both configured to communicate with each other over a radio link. The remote unit includes a sensor configured to activate a transmission from the remote unit to the base station upon detecting a hazard, triggering an alarm at the base station.
This method obtains the same limitations as those obtained by U.S. Pat. Nos. 5,650,770 and 5,963,130.
U.S. Pat. No. 7,053,822 (Rickerson, Jr.) discloses a wearable satellite tracker comprising, among other components, a satellite navigation receiver and a two-way satellite transceiver, powered by a portable power source, that can operate as a man-over-board device.
US patent application 20040113836 (Rickerson, Donald JR.) discloses a Wearable Satellite Tracking system comprising: A remote unit embedded in the personal flotation device, commonly called a life vest, with a battery for power, GPS receiver for obtaining accurate position information, alarm sensors that include a panic button to bring the unit to an alarm state, a satellite transceiver for transmitting the location and alarm information to a central tracking monitor, a system status indication that indicates to the wearer of the unit the ability of each of the subsystems to function correctly and optionally a satellite telephone interface to speak and listen to the operator at the Central Tracking Monitor when in an alarm state.
Both U.S. Pat. No. 7,053,822 and US patent application 20040113836, apply a navigational receiver (GPS) in the remote unit, so require a significant size and reduced battery life. Advantageously, U.S. Pat. No. 7,053,822 and US patent application 20040113836 use satellite communications, thus achieves a worldwide range, yet this approach takes its toll. Even Low Earth Orbit (LOE) satellites are typically deployed some hundred miles above the earth surface, hence require the portable unit to transmit at a relatively high power and consume significant battery energy. Consequently, such a portable unit cannot be small enough to be continuously and effortlessly worn by seamen and naval passengers.
US patent application 20020021231 (Schlager, Dan; et al.) discloses a man over board alarm system comprising: a remote unit including a navigational receiver for receiving navigational information defining a location of the remote unit, and a radio transmitter for transmitting the remote unit location; a base station including a radio receiver for receiving the remote unit location; the remote unit and the base station defining a separation distance between the remote unit and the base station; the base station including measuring means for determining whether the separation distance exceeds a predetermined limit, and means responsive to the measuring means for giving an alarm and a display for displaying the remote unit location, whereby, a separation distance exceeding the predetermined limit causes a man-over-board alarm and the base station displays the location of the remote unit.
U.S. Pat. No. 6,439,941 (McClure, et al.) discloses A sea rescue apparatus, comprising: a personal flotation device (PFD); a hydrostatic pressure sensor mounted on said PFD; a global positioning system (GPS) receiver mounted on said PFD; a radio transmitter mounted on said PFD; and a controller connected to said hydrostatic pressure sensor, said GPS receiver, and said radio transmitter; wherein said controller is programmed to transmit location data via said radio transmitter only when said controller detects a hydrostatic pressure signal having at least a selected magnitude for at least a selected duration.
U.S. Pat. No. 6,414,629 (Curcio) discloses a tracking system comprising, in combination: a target unit having a GPS receiver, a signal transmitter to send a signal including a position of the target unit, and a processor to calculate an optimal time interval for transmission of the signal; and a locating unit having a GPS signal receiver, a compass to provide a reference direction of the locating unit, a signal receiver to receive the signal sent by the transmitter of the target unit, a processor to calculate a range and bearing from the locating unit to the target unit, and an indicator to display the range and bearing.
US patent application 20020021231 and both U.S. Pat. Nos. 6,439,941 and 6,414,629 disclose tracking systems based on remote units that include both a navigational receiver such as GPS, and a radio transmitter to contact the base station and report the remote unit status. These two components included in the remote unit suggest, as mentioned before, that the implementation of this unit will probably require a significant volume and power source that will impede the unit from being small and lightweight and easy to be wom. Additionally, the radio connection between the remote unit and base station disclosed in US patent application 20020021231 and both U.S. Pat. Nos. 6,439,941 and 6,414,629 is tricky. If a long range communications is desired, then, as mentioned before, the remote unit will require a significantly large size and limited battery life; on the other hand, if the remote unit should be small and obtain a long battery life, then the communications range will probably be limited and particularly useless for single handed sailors.
All the methods described above have not yet provided satisfactory solutions to the problem of locating a man over board, worldwide, being a passenger or part of a crew or even a single handed sailor, where this man-over-board wears a small and lightweight device such as a wristwatch, comfortable to be continuously wom onboard and operate automatically in a man-over-board situation.
It is an object of the present invention to provide a system and method for the location of a person overboard, worldwide, being a passenger or a crewmember or even a single handed sailor, where this man-over-board wears a small and lightweight device such as a wristwatch, comfortable enough to be continuously worn onboard and operate automatically during a man-over-board situation.
It is another object of the present invention to provide a system and method for determining the location of persons overboard, by leveraging the location capabilities of current and future systems for determining the location of vessels and aircraft in distress, such as COSPAS-SARSAT.
It is also an object of the present invention to provide a system and method for determining the location of persons overboard, by leveraging the location capabilities of current and future radio beacons for determining the location of vessels and aircraft in distress, such as COSPAS-SARSAT EPIRB and ELT and PLB.
It is yet another object of this invention to provide a system and method to locate people in a distress situation, such as suffering a heart attack or being unconscious or intoxicated or severely injured or ill, by a remote station, where this person wears a small and lightweight device such as a wristwatch, that is practically comfortable to be worn and operate automatically upon detecting an alert situation.
It is another object of this invention to provide a system and method to locate objects that fall overboard vessels, such as containers, that while floating at sea present a severe navigational danger, especially to small and non metallic vessels.
It is another object of this invention to provide a system and method to locate objects, such as pets, vehicles, containers, valuables, hazardous materials and so on, by a remote station, where this object is attached with a small and lightweight and low power device.
Other objects and advantages of the invention will become apparent as the description proceeds.